The invention concerns an electro-mechanical pulse generator for producing electric pulses for setting, or alternatively correcting, an electronic digital display.
Swiss Pat. No. 558,560 discloses a device for setting an electronic digital display in an electronic clock or watch where the correction or setting of the display is accomplished by a control knob located on the exterior of the clock casing. By turning this knob it becomes possible to select by way of a contact spring, arranged at the stem of the knob, various output signals from a frequency divider located inside the clock. This causes pulses possessing various high frequencies to be fed into the electronic digital display, thus correcting their associated portions of the display by means of various pre-set pulse frequencies, as required. As an additional improvement of this device there is provided a separate RC or LC oscillator, likewise adjustable from the outside by a control knob, wherein the frequency of the correcting pulses fed into the digital display can be varied linearly in functional relation to the angle of twist of the control knob. For both species of the described display-setting device, there are further provided means which allow the display to be set either forward or backward.
The devices described require a very delicate handling by the person operating the outside control knob because the frequency divider output signals to be engaged are located very close to each other and because only a relatively limited angle of twist is available. Neither of these regulating devices, designed to correct the electronic digital display of a clock or watch, teach or suggest the solution of the problem with which the present invention is concerned.
Applicant's German Pat. No. 2,540,486 discloses an electronic clock with an electro-mechanical adjusting device for setting or correcting the electronic digital display wherein the previously described disadvantages are avoided. The adjustment of the display differs from the arrangement disclosed by the Swiss patent, by the use of individual impulses, produced by a pulse generator, whose frequency as well as direction are readily variable in a functional relation to the operational speed and direction of a control unit.
It is therefore an object of the present invention, to provide a display-regulating device which is inexpensive and suitable for series production by simplification of the mechanical and the electrical structure.
It is a further object of the present invention to provide a display regulating device which is not limited in its use to specific types of instruments with electronic digital display, and which allows the production of pulses in either direction, i.e. forwardly or rearwardly by simple electronic means.
The electro-mechanical pulse generator provided by the present invention is simple and easy to manipulate, making it possible to set very rapidly an electronic digital display at a desired value. Any errors in setting the display can be easily corrected because the device provided by the present invention permits a forward as well as a rearward direction of correction. The setting of a display value is accomplished by individual pulses which can be generated either slowly or in rapid succession in dependence upon the turning speed of a control element. This permits the direction of the correction produced by pulses--either forward or backward--to be clearly defined and therefore easily controlled by control logic. The pulses are fed into an UP-DOWN counter to actuate the unit specifically in forward or rearward direction.
Depending on the number of pulse-generating elements of a pulse generator and the gear ratio between the control element and pulse generator, or collector, it will be possible to produce, for example, 60 pulses per one turn of the actuating element. The person setting the display is not restricted by fixed correcting positions to be arrived at by a turn of the control element or by a correcting speed to be accomplished on the basis of feel and experience. There is assigned to each individual, adjustable display value a mechanical angular momentum which is noticeable at the control element by means of a lock-in of the pulse generator, or pulse collector.